/**
 * Copyright (c) 2006, Sun Microsystems, Inc
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of the TimingFramework project nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package equation;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.LinkedList;
import java.util.List;

public abstract class AbstractEquation implements Equation {
    protected List<PropertyChangeListener> listeners;

    protected AbstractEquation() {
        this.listeners = new LinkedList<PropertyChangeListener>();
    }
    
    public void addPropertyChangeListener(PropertyChangeListener listener) {
        if (listener != null && !listeners.contains(listener)) {
            listeners.add(listener);
        }
    }
    
    public void removePropertyChangeListener(PropertyChangeListener listener) {
        if (listener != null) {
            listeners.remove(listener);
        }
    }
    
    protected void firePropertyChange(String propertyName,
                                      double oldValue,
                                      double newValue) {
        PropertyChangeEvent changeEvent = new PropertyChangeEvent(this,
                                                                  propertyName,
                                                                  oldValue,
                                                                  newValue);
        for (PropertyChangeListener listener: listeners) {
            listener.propertyChange(changeEvent);
        }
    }
}
